I've used the older MB Quart 6.5's for years and have powered them with many different amps ranging from 75w rms per channel to 150w rms per channel. I've blown a couple of tweeters and a couple of the cheap cross-overs over the years but that's about it. I think you'll find that distortion is what blows speakers rather than overpowering them. I've upgraded all the crossovers on mine and have fine-tuned the amps and have not had any problems since. Unfortunately on a boat, there are so many other noises around it's sometimes hard to hear the speakers distort before it's too late. I also set the gains on my amps to a modest level just in case someone cranks the volume all the way up, the speakers won't distort and blow (added insurance I guess you would say).

I've used the older MB Quart 6.5's for years and have powered them with many different amps ranging from 75w rms per channel to 150w rms per channel. I've blown a couple of tweeters and a couple of the cheap cross-overs over the years but that's about it. I think you'll find that distortion is what blows speakers rather than overpowering them. I've upgraded all the crossovers on mine and have fine-tuned the amps and have not had any problems since. Unfortunately on a boat, there are so many other noises around it's sometimes hard to hear the speakers distort before it's too late. I also set the gains on my amps to a modest level just in case someone cranks the volume all the way up, the speakers won't distort and blow (added insurance I guess you would say).